1. Field of the Invention
This invention relates to a spring clutch device for permitting ON-OFF control of a drive mechanism, and more particularly to a spring clutch device for controlling the stop position of a cam member which controls paper feed in a copying machine or the like.
2. Description of the Prior Art
Gear clutches, friction clutches, and electromagnetic clutches, etc. have heretofore been utilized to permit ON-OFF control of a drive device, but all of these clutches have been of the type in which a clutch element is displaced to effect its change-over operation and required great forces for effecting the change-over and for holding the changed position. These controls have led to the tendency toward larger size of the clutches.
It has therefore been considered to eliminate such disadvantage by utilizing spring clutches instead of these clutches. For example, one of such spring clutches is disclosed in our U.S. Pat. No. 3,729,077, whereas these clutches have been complex in construction and offered problems in terms of reliability and cost.